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oxide7 writes "Since the advent of cellular phones, researchers have pondered whether a connection exists between cell phone usage and brain cancer. New evidence always seems to emerge to support or refute such a link. On Wednesday, another study was added to the list. A European study involving nearly 1,000 participants found no link between cell phone use and brain tumors in children and adolescents. This marks the 3rd study this month and the 4th major one this year, all with different conclusions."

Oh if I had mod points. You are so right and your formula can be applied to research done in various fields. I think Mythbusters presented the best research on the subject. They put Busters' head in a glass box with some alcohol soaked rags and a cell phone that was wired up to some kind of scientific instrument that measures radiation (yeah someone here will know wtf I'm talking about). They found that the radiation did spike a bit when making or recieving calls but it was within acceptable levels. And pre

I noticed the ones who said correlation was there (causes cancer) were from universities, whereas the other studies were international committees with no mentioned affiliation. I am pretty sure you are right on target.

Ummm, no they haven't. The underlying physics has been known for at least a hundred years and the appropriate experiments to confirm the theory were done to every thinking person's satisfaction long before cellphones even existed.

Anybody who thinks cell phones might cause cancer has no right to call themselves a "researcher". They're in it for the grant money, book sales and daytime TV a

A modern cellphone emits on the order of 1 W of radiated power. That would take an hour and a half [wolframalpha.com] to heat an adult brain up by 1 Kelvin, but our brains are liquid cooled [wikipedia.org], so that just can't happen.

If an increase in the temperature of the brain causes cancer, then people who work outdoors in tropical countries ought to get a very high rate of brain cancers. They don't. People who get fevers more often than average ought to get a high rate of brain cancers. They don't. The average person's body temperature c

you're wrong. cell phone radiation is the same kind as light, yes. but unlike light, it can cause a very little amount of heating inside your head. the question is, does that heating pose a risk? i don't think it does, but i'm not a scientist. it worries me why so many studies do not agree with each other.

Doing these studies makes as much sense as doing massive, expensive studies to figure out whether I can cause my neighbors to get cancer by thinking evil thoughts about them. In both cases, there is no remotely plausible physical mechanism for the direct effect as postulated. The only reason to do the cell-phone study and not do the evil-thoughts study is that the former appeals deeply to people's folk beliefs, which have been built up from decades of movies and comic books where "radiation" c

If only someone could go back in time and convince them to come up with another word to describe electromagnetic propagation. Think of all the time and money that could be saved. If it's not an ionized particle, IT'S DIFFERENT!

Actually, the fact that they are non-ionizing doesn't prevent them from harming DNA. Ionization loosely means that the power is sufficient to destroy a base pair in a DNA chain (via striping of an electron), if the full energy of the wave packet is absorbed. Ionizing radiation is guaranteed to hurt you if it is absorbed by your body (e.g., it will ionize something whether that is protein or DNA). My perception of why "non-ionizing" doesn't mean it is safe comes from a (tangential) education in terahertz radiation (e.g., microwaves). Simply put, just because the radiation may be low in power when averaged over time and space, the instantaneous energy density of the radiation might make it unsafe. DNA can be harmed through lots of different ways other than ionization (strand separation, mutagens, denaturing, etc.)

For an ocean analogy, just because the ocean has an RMS wave height of 5 feet doesn't mean that *all* the waves will be 5 ft tall. Instantaneous peaks (in space and time) will discharge sufficient energy (albeit non-ionizing) into DNA to cause the strands to separate (and be subject to other effects accordingly). For a gadget example, take the microwave. It isn't ionizing. It doesn't directly cause cancer, but if an organism is subjected to sufficient microwaves of power to denature proteins, the process will cause upticks in cellular metabolism to repair those proteins. I for one do believe that the uptick in metabolism does in fact lead to a higher incidence of cancer (though metabolic studies vs cancer rates are really not well documented in my book and mostly involve healthy people starving themselves).

I think the best take on cell phone radiation, for which sadly cannot attribute, was from a UK doc several years ago who was worried that the digitization of cell phone signals (vs analogue), while it would lead to a much lower RMS would also lead to bursts of *very* high instantaneous energy. This might denature proteins over time, like cooking an egg millimeter by random millimeter.

Forget studies on people with cell phones for the next decade or so. People are complicated and are difficult to pin down w.r.t. a cause of a disease. I think we probably need to spend more money on actual fundamental (microbial) research on non-ionizing radiations effect on cellular growth (such as http://www.biomedsearch.com/nih/Cell-phone-radiations-affect-early/20355324.html [biomedsearch.com]). As for myself, right now I have no idea if they are safe, but I for one know that just being "non-ionizing" isn't enough.

I have seen PET-scans from a study where the subject was injected with doped glycose molecules and using a GSM 800 MHz phone while inside the detector. The scans showed a high concentration of glycose -- a blob in the image -- right next to where the antenna was, and only normal levels elsewhere in the head.
Mind you this was somewhat older model of an Ericsson GSM phone with only a single-band that had an actual external antenna.

Here's the thing: non-particle ionizing radiation (e.g. ultraviolet light) is fundamentally just higher energy because of the higher frequency. Claims that UV causes damage while lower frequency RF signals can never cause damage are just plain contrary to reason. Nothing else in nature has a sudden threshold like that; there's always a continuum, such that you start to see significant numbers of additional deaths at some concentration, with near complete destruction of the population at some point, but th

I think you're simplifying too much. Its better to quantify things. UV radiation is 1,000,000 times more energetic than radio. So the magic threshold you are talking about spans a factor of a million. Another way to put it is that the cutoff is not arbitrary at all. If you shine light that does not contain photons energetic enough to knock electrons away from their nuclei, it does not matter how long you do it for, or how bright the light is. You will never get ionization. This has been known for 100 years.

Although it doesnt cause cancer, the radiation is nonetheless interacting with molecules (in this case causing thermal excitation of water) in your body.

It is not unreasonable to have an interaction with a radio wave perturb a molecule either thermally, magnetically, or otherwise, and result in a modification to some biological pathway. If that pathway has to do with healing of damaged DNA then you will very easily get cancer, despite the lack of ionizing radiation. I dont know the biology of the brain ve

1000W at 200mm distance equals (10/200)^2*1000 = 2.5W at 10mm. Cell phones burst at 3-5W (depending on local regulations). The oven is directional while the phone is omnidirectional, but the short distance means it can't be discounted.

When was the last time you found a cell phone that worked at 3-5 watts? The old bricks and bag phones from the mid 80s were 3 watts, today's phones are about 1/10th of that. Additionally there is a reason that microwave ovens work at the specific frequency that they do, it's because that frequency causes the energy to be transferred to water molecules and cause them to heat up, if you changed to either a higher, or a lower, frequency the microwave oven would stop being able to cook your food. Cell phones do

sunlight is also non-ionizing. so can you look at the sun without burning your retina? nope.i think there is no relation between cancer and cellphones, but it would be wrong to dismiss the though just due to it being non-ionizing.

Sorry to tell you this, but the whole banana thing was a mistake. Your body maintains an equilibrium with respect to potassium. When you eat a banana, you quickly excrete just as much potassium as you ate. Negligible net increase in your radiation dose.

Technology and frequencies have all been changing over the last few years. Even analog to digital. I would be interested in seeing if the studies that all show harm are for the same technology. And the harmless studies are for a different set of frequencies.

Different frequencies affect things differently. eg microwave radiation is absorbed easily and heats our food. xrays mostly go straight through tissue. Different frequencies will have different penetrating capabilities. One could potentially be more damaging to our skin/brain than the other.

>This marks the 3rd study this month and the 4th major one this year, all with different conclusions.

If we were talking about anything else, the obvious conclusion would be that there isn't even evidence for correlation let alone causation. This will continue until the next Scary Thing (tm) comes along to replace cell phones and smart meters.

Published in the International Journal of Oncology, and carried out by researchers from the University Hospital of Örebro and Umeå University (Sweden), the study found that long-term usage increased the risk of all malignant tumors by 30 percent, and astrocytomas in particular by 40 percent.

People who started using mobiles as teenagers, and have done so for at least 10 years, were 4.9 times more likely to develop astrocytoma as compared to controls, the researchers added.

Neither article bothers to give enough identifying information for this study for me to actually find the paper (even further reinforcing my impression of widespread journalistic incompetence...). Anybody have a link at least to an abstract?

I'm amazed at the sheer number of people down here in the south who drive their expensive luxury cars and trucks with the mobile phone glued to their ear by their hand, oblivious to the situation and other drivers around them.

You'd think that if they can spend $30-60K they could buy a $40 Bluetooth speakerphone or ear piece?

Actually, the discussion on this includes messages with interesting points. The most fun might be the observation that one interpretation of the graph is that the increase in cell-phone users matched the levelling-off of the total cancer incidence, implying that cell phones are preventing a significant portion of the cancers we'd have otherwise.

Of course, fun stuff like this is likely to be drowned out by the chorus of "correlation doesn't imply causati

Nonlinear effects are possible, like where two photons are absorbed then only one is emitted. So non-ionizing radiation could in theory interact in a way to produce ionizing energy. It's also possible that some structures are exquisitely sensitive to particular frequencies of radiation.

But a closer look shows just how unlikely such phenomena are. The probability of such interactions depends on there being sufficient energy density - you see them with megawatt lasers but not at the power levels where cell

First of all, there are ionizing and non-ionizing photons. The difference is the energy/frequency/wavelength. Visible light, infrared, radio are all relatively low energy and non-ionizing. X-rays and gamma rays, OTOH, are ionizing.

Second, your assertion that there are no processes that can convert non-ionizing radiation to ionizing radiation is false. I've done it myself in the lab - a 10Mw picosecond pulse neodymium YAG laser puts out light in the infrared (non-ionizing). But with frequency doubling opt

In other words, you now admit that my original point, which was that while it's possible to turn non-ionizing radiation
to ionization radiation, the chances of anything in a human body doing it are vanishingly small, was in fact correct.

Entirely relevant, actually. The reason I brought it up is because it has various been asserted that an ionizing effect in this situation is possible, and others have claimed it's impossible. I don't know about you, but when I want to consider whether or not something is possible in a given situation, I look at the actual physics and see what's involved in getting it to happen. And we both know, what's involved doesn't seem likely to exist (ok, that's an considerable understatement) as a combination of what

its not just lack of education, there's a general atmosphere of misinformation in news sources. my mother (a civil engineer) thinks cellphones and laptops(!) cause cancer, if operated too close to the body. this is due to misleading, sensationalist reports in newspapers and tv. and these guys doing all these contradicting studies are not helping either.

Actually it is in the UV band that radiation become ionizing. Near UVA(300-400nm) is non-ionizing. Middle
and Far UVB/C (200-300nm) is ionizing. The latter(UVB/C) causes DNA damage directly. UVA can contribute to
cancer, but it is indirect through interactions with radicals. Nobody has ever said that there are not chemical interactions
that can be influenced by non-ionizing radiation (chlorophyll and blue/red light comes to mind). However, cell phones are in the microwave region.
If you can show an organic molecule that reacts chemically at these frequencies, I suspect there is a Nobel Prize in it for you. So far
all anyone has been able to show is heat.

Thank you. His theory/assumption was far too vague. We need to measure the amount of radiation occuring on most current models in various modes of daily use to even grasp a correct baseline before we can calculate potential damage to tissue etc. It's just basic facts with no hidden agenda that we need to formulate a valid opinion.

Radiation is just a scary word for light. Lightbulbs cause radiation. Heat causes radiation. Your own body emits radiation. Cancer is only caused by radiation that is at wavelengths that can damage DNA.

Assuming the parent *already* gave his kid a cell phone... what's wrong with the research about said usage? The kid is already using it, wouldn't it just be measuring the results? And if you don't want to give your kid a cell phone, it would still just be measuring the results. It doesn't seem like the study is asking them to do anything different than normal cell phone usage, which they very likely are already doing. Granted, I'm not sure of their actual methods... but since they are trying to find a l

This, like most cancer studies, is statistical. That is, the subjects self-select themselves into control or experimental group independent of the existence of the study.

The problem there is that self-selection introduces a lot of potential for confounding influences.

The huge advantage and why they're done in spite of such a serious shortcoming is that since the subjects self-select independently of the study's existence, the researcher bears no responsibility for the outcome.

Imagine this statement: "Sunlight is not ionizing radiation therefore it is unthinkable that it can cause cancer."

On another topic, the study is flawed in that it only tracked children over a limited period even though that was several years, and therefore cannot make assertions that something does not cause cancer, as it omits long-term development triggered many years before. It is clear from chemical environmental studies that carcinogens can take long times to produce effect.

Yes, and in the case of covalent bonds, or hydrogen bonds, breaking bonds is not ionizing anything, so what is your point?DNA is not an ionic solid, in case you are confused about that. In fact, I'll say that there are *no* ionic solids in the human body under normal conditions (i.e. you didn't just eat some table salt which has not yet fully dissolved in your mouth), just to be safe.

I went to make sure I used the right definition. And lo! I correct myself. Breaking the bond in ionic materials is dissociation and not ionization. But in common in ionization and dissociation is that energy causes the action. Certainly UV can have enough energy to do either, in the right cases.

Now, going back to the original issue, some RF energy can most certainly ionize although it depends on the frequency and power level. A simple example is in the semiconductor industry where RF applied to plasma chamb

Guys, I was illustrating flawed thinking - my whole post was about flaws. I was not asserting that UV cannot deliver enough energy to break bonds. Of course it can.

I'm still kinda lost but I'm willing to believe you're saying something. Want to try again?

As far as your other points about density of cell towers, going from an area with a single distant tower to an area with great cell coverage (i.e. an increase in cell tower density) would cause a decrease in phone transmit power at the phone of tens of dB, and a decrease in absolute power of at least several hundred milliwatts, which would result in a drastically decreased SAR. The increase in power from the surroun

I have a question. The worst-case received power a cell phone is designed for doesn't really say what peak emitted power a cell tower emits. Even with inverse-square law, what are the actual numbers for tower antenna radiation? I don't any good numbers available but believe it's around 35 to 100 watts per bay at phone frequencies. How much at harmonics of 800 MHz? How much at frequencies caused by nonlinear rectification by corroded materials? I don't know. Need more info. Can''t sleep, clowns will eat me.

The nature of EMF from transmitters is that most communications and food preparation equipment are operating at near the resoant frequency of water:

No, that's wrong. Dipole resonance of water molecules is around 20 GHz. Microwave ovens are 2.5 GHz and 915 MHz. Those frequencies are allocated as ISM bands. All RF causes heating by absorption, even light.

cell phones and WIFI are operating near the resonant frequency of water to improve their line-of-sight communications through the atmosphere, while microwave ovens actuallty agitate the water molecules in edible food

No, that's wrong. If something absorbs RF and turns it into heat, it's not going to pass it through without loss as well. You're claiming two contradictory things in the same sentence.

to generate heat that supposedly cooks the food if not change the chemical structure of it to something worse.